Scars on Mars suggest recent glaciers
MSNBC

A vanished glacier with a mysterious calling card suggests Mars went through many ice ages in its very recent past.
A fresh look at images from the Mars Reconnaissance Orbiter indicates thick glaciers may have existed in the past 100 million years in the planet’s equatorial region, but vanished after planetary wobbles changed the climate in certain areas.
“We’ve gone from seeing Mars as a dead planet for three-plus billion years to one that has been alive in recent times,” said Jay Dickson, a geologist at Brown University and lead author of the study. “[The finding] has changed our perspective from a planet that has been dry and dead to one that is icy and active.”